Hi, how this question is answered as below? I don't get t can you show me step by step please

11-10. Arbor Systems and Gencore stocks both have a volatility of 40%. Compute the volatility of a portfolio with 50% invested in each stock if the correlation between the stocks is (a) + 1, (b) 0.50, (c) 0, (d) -0.50, and (e) -1.0. In which cases is the volatility lower than that of the original stocks? 40% stock vol corr 50-50 Port 1 40.0% 0.5 34.6% 28.3% -0.5 20.0% 0.0% -1 Volatility of portfolio is less if the correlation is